THE ANIMAL KINGDOM

The animal kingdom can be divided into 9 smaller groups The animal kingdom can be divided into 9 smaller groups. Each group is called a phylum.

PHYLUM PORIFERA Sponges

Phylum Porifera •Sessile-stays in one place •Most simple multicellular organism •No tissues or organs •Central body cavity •Osculum- large opening(s) at top •Pores for incurrent water

Sponges are sessile animals (they spend their lives attached to rocks)

Water enters the small pores of a sponge, travels through canals, and exits through a large hole at the top of the sponge.

PHYLUM CNIDARIA Jellyfish, sea anemones, corals

Phylum Cnidaria •Two forms: Polyp and Medusae Polyps mostly sessile •Medusae free swimming •Cnidocytes- stinging cells on tentacles •Gastrovascular cavity- central body cavity

Members of this phylum have tentacles with stinging cells.

Cnidarians can have one of two body shapes: an umbrella-shaped medusa form, like the jellyfish on the left, or a vase-shaped polyp form, like the sea anemone on the right.

Coral reefs contain many members of Phylum Cnidaria.

PHYLUM PLATYHELMINTHES Flatworms

Phylum Platyhelminthes •Diffusion is used in place of important body systems. •No real vision only senses light with eyespots •Examples: Flukes and Tapeworms •Reproduce asexually by fission •Reproduce sexually by cross fertilization

The worms in this phylum are all very thin and flat, like this parasitic liver fluke.

All flatworms, including this planarian, have bilateral symmetry.

Flatworms are the first animals to have a head Flatworms are the first animals to have a head. Note the hooks and suckers on the head of this tapeworm.

PHYLUM NEMATODA Roundworms

Phylum Nematoda •Roundworms are found everywhere •In one cubic meter millions can live •Some Nematodes are parasitic •Trichinella is a muscle parasite found in pig meat; Hookworms are intestinal and drink blood of stomach; and Filarial Roundworms infect lymphatic system and cause Elephantiasis

Nematodes are not segmented; their body surfaces appear smooth.

Many nematodes are parasites, such as this pork worm named Trichinella.

Nematodes have a complete digestive tract, with a mouth at one end where food enters, and an opening at the other end where wastes exit.

PHYLUM MOLLUSCA Clams, snails, squid, octopus

Phylum Mollusca •Shell made of Calcium Carbonate •circulatory Cephalopods •Mantle lays down the shell Open system except for Radula tongue made of chitin used to scrape for food •Bivalve named for number of shells •In some the shell is internal

Most mollusks have a hard shell covering their soft bodies.

Clams have a wedge-shaped muscular foot used for locomotion.

Mollusks breathe by means of gills.

Not all mollusks have shells. This squid does not.

This octopus does not have a shell either, but it is still a mollusk.

PHYLUM ANNELIDA Earthworms, sandworms, leeches

Phylum Annelida •Segmented worms are capable of more complex movements •Have a closed circulatory system •Have five pairs of “hearts” •Pharynx draws in food •Crop stores food •Gizzard grinds food up •Then it is passed into the intestine where nutrients is absorbed and out the anus

Annelids have bodies that are segmented (divided into sections).

Annelids have a circulatory system to pump blood Annelids have a circulatory system to pump blood. This earthworm has 5 hearts!

Annelid worms have a body cavity called a coelom which provides room for organ development.

PHYLUM ARTHROPODA Crayfish, lobsters, crabs, insects, spiders

Phylum Arthropoda •Most dominant animals on Earth •Exoskeleton “suit of armor” made of chitin •Efficient gas exchange allows rapid supply of oxygen to muscles •Well developed sensory system •Well developed nervous system •Well developed circulatory system

All arthropods, including this tick, have jointed legs.

Arthropods have a crunchy shell called an exoskeleton.

Arthropods have very well-developed sense organs.

PHYLUM ECHINODERMATA Starfish, sand dollars, sea urchins

Phylum Echinodermata •The name echinoderm is Greek for “hedgehog skin” •Use a water-vascular system for locomotion, respiration, and food capture •Lack a circulatory system •Have regenerative capabilities

Echinoderms have spiny (prickly) skin.

Adult echinoderms have radial symmetry.

The bottom of this starfish is covered with tube feet for locomotion.

PHYLUM CHORDATA Fish, amphibians, reptiles, birds, mammals

Phylum Chordata •Deuterostome development-anus formed first •Characteristics of Chordates: 1. Notochord 2. Dorsal, hollow nerve cord 3. Pharyngeal gill slits / Respiratory Openings 4. Post-anal tail

Members of Phylum Chordata have a backbone (they are vertebrates).

Phylum Chordata can be subdivided into 7 classes: AGNATHA CHONDRICHTHYES OSTEICHTHYES AMPHIBIA REPTILIA AVES MAMMALIA

Class Agnatha includes jawless fish such as lampreys Class Agnatha includes jawless fish such as lampreys. They are parasites on other fish.

Class Chondrichthyes includes fish whose skeletons are made of cartilage, such as sharks, rays, and skates.

Class Osteichthyes includes fish whose skeletons are made of bone.

Class Amphibia includes semi-aquatic animals with moist skin Class Amphibia includes semi-aquatic animals with moist skin. They must return to the water to breed.

Class Reptilia includes snakes, lizards, turtles, crocodiles, and iguanas. They have dry, scaly skin.

Members of Class Aves have wings and feathers for flight.

Class Mammalia includes animals with hair or fur Class Mammalia includes animals with hair or fur. Females have mammary glands to nurse their young with milk.

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